Harlow pressed Arnold for specifics and asked whether Cohen, who is under criminal investigation on suspicion of campaign-finance violations, bank fraud, wire fraud, and illegal lobbying, was cooperating with law-enforcement officials.

Arnold scratched his chin and appeared to be lost in thought before replying.

"This is too important to me to 'eff' around — and you know the word I'm talking about," Arnold said. "This is serious to me, Poppy, and I'm not 'effing' around."

Harlow pushed for specifics: "Do you not want to answer the question," she asked.

"No." Arnold said.

Cohen threw some cold water on Arnold's remarks Friday evening, saying that he is not spending the weekend with Arnold. Pointing to a picture of himself with Arnold that was widely circulated on Friday, Cohen said, "this was a chance, public encounter in the hotel lobby where he asked for a selfie."

"Not spending the weekend together, did not discuss being on his show nor did we discuss POTUS," Cohen said.

Arnold will star in the Viceland show, "The Hunt for the Trump Tapes," which features Arnold searching for unflattering recordings of Trump. During the 2016 presidential election, several recordings of Trump were brought to light, including the infamous "Access Hollywood" tape that featured him boasting about groping women.

Arnold previously told NBC News that he and Cohen spoke in Manhattan to discuss "taking Trump down together." Cohen, who is dubbed Trump's "bulldog," was being betrayed by Trump, according to Arnold.

"This dude has all the tapes — this dude has everything," Arnold said, referring to Cohen. "I say to Michael: 'Guess what? We're taking Trump down together,' and he's so tired he's like, 'OK,' and his wife is like, 'OK, f--- Trump.'"

"We've been on the other side of the table, and now we're on the same side," Arnold added. "It's on! I hope he sees the picture of me and Michael Cohen and it haunts his dreams."

Arnold later clarified his statement on Twitter and appeared to walk back some of his claims.

"Michael Cohen didn't say Me & him were teaming up to take down Donald Trump!" Arnold tweeted. "Michael has enough Trump on his plate. I'm the crazy person who said Me & Michael Cohen were teaming up to take down Trump of course. I meant it. Michael doesn't get paid by Vice."